1. Field of the Invention
The present invention relates to a Broadband Wireless Access (BWA) system. More particularly, the present invention relates to an apparatus and a method for providing a MultiCast and BroadCast Service (MCBCS).
2. Description of the Related Art
In general, communication systems were developed based on providing a voice service. With advances in technology, communication systems now provide data services and various multimedia services as well as the voice service. However, the voice oriented communication systems are not able to satisfy users' service needs because of their relatively narrow transmission bandwidths and expensive fees. Additionally, advances of the communication industry and users' increasing demand for an Internet service raise the necessity for communication systems that efficiently provide an Internet service. To respond to this demand, a Broadband Wireless Access (BWA) system is presented with enough bandwidth to meet the users' increasing demand for an efficiently provided Internet service.
The BWA system integrally supports not only a voice service, but also multimedia application services such as various low- and high-speed data services and high-definition video. The BWA system is a radio communication system capable of accessing a Public Switched Telephone Network (PSTN), a Public Switched Data Network (PSDN), the Internet, an International Mobile Telecommunications (IMT)-2000 network, and an Asynchronous Transfer Mode (ATM) network in a mobile or stationary environment based on radio media using bandwidths of 2 GHz, 5 GHz, 26 GHz, and 60 GHz, and supporting a data transfer rate over 2 Megabits per second (Mbps). The BWA system can be classified as a broadband wireless subscriber network, a broadband mobile access network, and a high-speed wireless Local Area Network (LAN) based on the mobility of the terminal (stationary or mobile), the communication environment (indoor or outdoor), and the channel transfer rate.
As a representative example of the radio access scheme of the BWA system, the Institute of Electrical and Electronics Engineers (IEEE) 802.16e standard is standardized by the IEEE 802.16 Working Group, which is an international standardization organization.
Compared to a conventional radio technique for providing a voice service, the IEEE 802.16e standard can transfer a greater amount of data within a shorter time using the wide data bandwidth and allow more users to efficiently share and utilize the channel (or resource). Also, with Quality of Service (QoS) guaranteed, the users can enjoy services of different qualities according to the service characteristics.
Yet, a network access technique of the WiMAX Forum, adopting the IEEE 802.16e standard for the radio access network, defines only a one-to-one communication method for the multimedia service transmission. In terms of the amount of data provided by the multimedia service and a great number of users who request a specific multimedia service at the same time, the current one-to-one communication method of the WiMAX Forum inefficiently uses the limited radio resources available for the transmission of the multimedia service. This increases the burden to the user of the multimedia service and limits the number of users who may receive service at the same time.
According to a conventional MultiCast and BroadCast Service (MCBCS) method, to request to receive a specific channel, a terminal generates an MCBCS connection through a DSx procedure with a base station and receives a MAC parameter such as Multicast Connection IDentifier (MCID). Every time the user requests a channel change, the terminal which is receiving the specific channel needs to perform a Dynamic Service Deletion (DSD) of the existing channel and a Dynamic Service Add (DSA) of a new channel with the base station. This causes a channel transition time delay and the successive DSx procedure may waste radio resources.
As discussed above, to address the shortcomings of the conventional MCBCS method and to provide more efficient service in view of the user and a service provider, a new definition of functions of network entities and an information delivery method between the entities are needed.